As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Saturday 3 November 2012

Alaska trumpeter swans filling historic range

ANCHORAGE, ALASKA -- It was likely easier than ever to see a migrating trumpeter swan this year, as the big white birds continued a remarkable comeback from near extinction in the Lower 48 states and much of their Alaska habitat, a federal wildlife biologist said.

"They still have not recovered to their full range that they once occupied prior to the 1880s, but they've done fantastically in Alaska," said Deborah Groves, who has counted Alaska swans since 1990.

A 1968 Alaska census found just 2,847 of the birds. Random sampling in 2010 estimated 25,347 - a nearly ninefold increase.

Trumpeters are known for their distinctive call that the Cornell Lab of Ornithology calls "hollow, nasal honking." The Alaska Department of Fish and Game says it's deep, like a French horn.

With 7-foot wingspans, trumpeters are North America's largest waterfowl. Males average 28 pounds, females 22 pounds, and eggs are up to 5 inches long, the department says.

The birds were hunted throughout the 1800s for meat and feathers, which made fine quill pens. By the early 1930s, Groves said, there were only 69 known trumpeters in Yellowstone National Park.

Hunting ended and biologists made a happy discovery when they began bird work in Alaska: A remnant population of a couple of thousand trumpeters remained, Groves said.

Alaska biologists did their first formal trumpeter survey in 1968, another in 1975 and every five years since then.

"They were increasing almost exponentially for a while," Groves said.

Biologists in 2005 detected a continued boom, even though they suspected the habitat of the birds was saturated. By 2010, the count switched to sampling rather than a census because of the trumpeters' wide range.

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